Thermostatic liquid-level regulator.



Patented Dec. 17,1912.

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W. EAST, 11.1. DOBBS 1111. s. HOWKINS. THLRMOSTATIG LIQUID LI'IVIEILA REGULATOR. AIPLIVATION FILED JUNE l0| 1911.

THEBMOSTATIG LIQUID LEVEL REGULATOR.

APPLIOATION FILED Jim1: 1o, 1911.

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W. EAST, A. E. DOBBS & J. S. HOWKINS.

THEEMOSTATIO LIQUID LEVEL REGULATOR.

APPLIOATION FILED JUNE 1o, 1911.

Patented Dec. 17, 1912.

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ZZZZCLSyQSe -UNITED sTATns PATInvr` onirica. f

WALTER EAST, or BoURNEMoUTH, ENGLAND, ARCHIBALD EDWARD DoBBs, `vor CAB.-l RICKFERGUS, IRELAND, AND JOHN sHmLEYHoWKINs, ,or FULHAM, LONDON,v

ENGLAND.

THEnMosTATIc LIQUID-LEVEL REGULATOR.

Patented Dee. 17, 1912.

Application filed June 10, 1911. lSerial No. 632,448.

T0 all 'whom t may concern.'

Be -it known that we, WALTER lElAs'r,

ARCHIBALD EDWARD Dones, and JOHN SHIRLEY HoWKINs, all subjects ofy the King of Great Britain, residing, respectively, at Bournemouth, Hants, England; Carrickfergus, Antrim, Ireland, and Fulham, London, England, have invented certain new and useful Thermostatic Liquid-Level Reguscribed in the specification of our British Letters Patent No. 5,587 of 1909.

The present invention Vis designed to provide al simplev and convenient apparatus operating on the same principle, which can be easily lit-ted to the boiler entirely from the outside, and shall be readily accessible for 'inspection and repairs, while at the same time obviating any necessity for removing any manhole covers or otherwisel interfering with the ordinary fittings of the boiler to which the device is to be applied.

According to this invention, the thermostatic apparatus is so arranged that the boiler water, when at. the proper level, enters a plain tube or chamber situated at the said level and subject only to the thermal action of a medium having a higher temperature than thev boiler steam, such for instance as' superheated steam, hot gases or a gas flame as distinguished from known thermostatic arrangements which have been proposed to be placed outside ,of the boiler, and which (although heated by hot gases) have had the -feed water introduced directly into them and therefore have been liable to have their temperature interfered with by the cooling action of said feed-water and by the inter- The said plain tube may itself form the expansible -device of the thermostat, but this is not strictly essential, as in some cases it may be separate therefrom, although arranged to modify orl control the temperature of the expanding device. 5

To more clearly define what is meant by a plain tube in this case, it may be stated that the term -is used herein to mean a tube or chamber which is simply arranged to 'receive steam or Water from .the boiler, according to the level, instead of being combined 4(as in the known arrangements referred to) with additional internal tubes or fittings which serve both to receive the feedwater and also to directly control the iiow of such feed-water.

If a steam jacket or the like be used around the plain tube or eXpansible device of the thermostat, there is led into the same,

superhe'ated steam, gas or tluid,lfrfom any convement superheatmg device, fsuch as a `system of coiled tubes, suitably situated in` the boiler furnace o r in the path of the products of combustion, or even having an independent source of heat. This steam, gas or fluid may if desired be drawnv from the boiler itself and after it has passed first through the superheater and then through the jacket of the thermostatic tube or eX- pansible device, may in some cases be led away to the engine or other apparatus which the boiler is feeding. In other cases however the tube or expanding device maybe heated directly, say by a gas flame.

ln general, the expansible thermostatic device or tube is connected with. a valve of anysuitable kind mounted on or connected with the boiler shell or framing, the arrangement being such that when the device expands beyond a certain definite limit for which it is set, it will open the valve and thereby bring about a further admission of liquid to the boiler. Usually this valve w1ll be a steam -valve so arranged as to start a pump or injector when it is opened. It may however be a water valve controlling the iiow of water'under pressure into the switch may be used instead of a valve. Such valve arrangements in themselves form no part of the present invention however.

In order that the invention may be clearly understood and readily carried into eilect reference will now be had to the accomboiler, or in some cases an electric contact panying diagrammatic drawings which illusthe improved apparatus and in which Figure 1 is a longitudinal section of a thermostatic regulator in which a plain hori- Zontal tube is surrounded by a plain tubular steam jacket, and in whichthe lengthenlng and shortening of the tube gives the vthermostatic action. Fig. 2 is a plan of this arrangement. Fig. 2a is a detailview herelnafter referred to. Fig. 3 is a corresponding view of an analogous arrangement in which however the thermostatic tube is surrounded by a spiral tube for the superheated steam instead of by a plain steam jacket. Fig. 4 illustrates thevgeneral arrangement for the connections of the thermostatv with the boiler, and also shows a further modification in the construction of the thermpstat. Fig. 5 illustrates a modification 1n which the expansion and contraction of the outer or j acketing tube is employed to give the thermostatic action. Fi 6 illustrates an apparatus heated by a gas jet instead of by a steam jacket.

Throughout the drawings the same letters of reference are used to indicate analogous parts. Referring more particularly to Figs. 1 and 2 a and b represent inner and outer tubes or vessels which are secured at one end in a hollow casting or block c having anfinlet pipe c screwed into the boilershell d at the proper water level. The pipe c ma contain a shut-olf valve or tap if desire The tube a is so arranged thatit lies in av horizontal lane at the mean'water level.

Aline of theboiler, so that when the water is at this the proper) level it ,enters the said tube a reely. The tube Z is supplied by a plpe b* with steam or other fluid' superheated by any convenient means, such as' a tubular coil d (Fig. 4) arranged in the boiler -furnace (Z2 asin the patent above referred to. This tube b forms therefore a hot jacket for the inner tube a, and mayin its'turn be provided with a laggmg or covering' of non-conducting materialto prevent the temperature of the atmosphere from affecting it. These two tubes form therefore a heat exchanging system between the boiler water in a and the superheated fluid in b, and the thermostatic action depends upon this exchange of heat, as will be hereinafter more fully explained.

e is an extension carries a feed-contro lin device or valve arrangement f and contains a bentor bell-l lever g or other con-v crank multiplyin trivance for working the latter.

In the example shown the device f is a valve which may be of any suitable construc- `tion such as a double piston valve (as shown) for instance. It is arranged to control the passage of steam from the jacket iece or casing which,

either to a pipe f', connected for example` With the live-steam main, or to a pipe f2 leading to the feed pump, so that when the boiler water level sinks and the valve f descends under the control of the thermostat, the jacket steam flows to t-he said feed pump and puts it in operation.

The lever 7 is .connected at its angle or knee g to a block h screwed into the tube a., and the short or vertical) arm of the lever is connected at g2 to an inextensible rod orv device z'. This inextensible device, shown in the form of a plain rod for convenience, may be made of any suitable non-expanding or practically non-expanding metal or alloy,

or it may be constructed on the well-known grid-iron pendulum principle, so that it will not vary in length with variations in temperature. Its object is to provide an immovable connection or anchorage for the fulcrum pin g2 at the end of the short arm of the bell crank lever. This latter arm may vmoreover be forked and engage (see detail view Fig. 2a) in an annulargroove or collar z" in the end ofthe rod i, thus permitting the rod'whichis screwed into the block c, to

fbe turned inthe said block to adjust it to the exact length when fitting the parts together,'as will be clear from the drawing.

By reason of its connect-ion with the inextensible device i, the fulcrum g2 of the leverjis held in one delinite position, while the knee art g ymoves to and fro as the tube a varles in length, and thus an angular movement is imparted to the lever which causes its free end tooperate to feed control valve or'device The action will be'readily understood When the tube a is partly or entirely full of water, which enters it from the boiler when the Water level is correct, the temperature of the said tube will be nearly the same as that of the water, in spite of the fact that the` tube lmay be jacketed with superheated steam. This is owing to the fact that they water possesses a much greater heat absorbing capacity than does the steam, and opposes the heating effect of the superheated steam'. At this time the thermostatic tube is at its ordinary working temperature and its length is normal, while the feed control valve or device is so adjusted that it is just inoperative un er these circumstances. If

therefore the water level falls and the tube a becomes empt the said tube increases in length under t e now unopposed heating action of the superheated steam, and through lthe lmedium of the lever g, operates the valve j through thevarrangement, in order to keep more branch tubes leading into the latterY from different points along its length. Release outlets for steam may beprovided to allow a constant fiow of superheated steam such superheated steam in the jacket always fresh and of the full temperature.

The thermostatic device instead-of being straight as shown, may, by vhaving the tubes a and b of curved shape begbent or looped to allow for expansion, and may be carried yby any suitable devices let into the boiler 'and provided with removable plugs for cleanout the tube in case it should become obstructed. In some instances it may be fitted to lie inside the boiler, or in a tube or casing let into the same, and be at or near the center line of the boiler where the motion of the Water, in a marine boiler for instance, will probably be least.

The jacketedthermostat tube, in addition to being curved or bow shaped as just indi' cated, may be so arranged that the water has access to both ends of it, or so that one end is connected with the water space of the boiler while the other end is connected with the steam space either directly or by any 30 'i suitable connecting tube.

Referring now to the arrangement shown in Fig. 3, it will be seen that the-feed con-` trol device or valve f and lever g are car ried on an arm or bracket'y instead of being supported on the steam jacket. Moreover the latter is now formed by a tubular coil 71 surrounding the inner tube a. This coil has an inlet pipe bx and an outlet pipe '60, and is inclosed in a sheathN or casing 7c filled with suitable non-conducting material or lagging. The hollow space inside this jacket may be filled with air or with a liquid which willbetter facilitate the exchange of heat between a and b. In other respects the arrangement is analogous to that of the Fig. 1 arrangement as will be clear. The valve f may be combined with a spring tending to keep it closed. i The general view shown in Fig. 4, illustrates the main arrangement of the parts, the steam for operating the thermostat being led from the dome or steam space of theboiler al by a pipe d* to any convenient superheater, such as a coil d arranged in the boiler furnace d2 whence it passes by the pipe bx to the thermostatic apparatus. The modification of the latter shown in this ligure 'is divided into two parts, the upper part (05,12) forming the heat-exchanger, being distinct from the lower part (a, f, g) which forms thefactual thermostat. The construction of the lever and valve parts and f and of their supporting bracket is the 'same as that shown at the left hand end of vplified on this account.

the jacket or tube bis more orv less cooled or varied in temperature by the action of the. tube a and then passes downthe pipe bf into the expansion device or tube a after iiowing throughthe latter, it passes thence through a connecting pipe d* back to the steam main (Z3. Owing to the` variations in its temperature caused by the boiler water in the tube a, the said steam sets up corresponcling variations in the length of. the tube a', which latter through the lever g and valve f, controls as before the feed supply to the boiler. With this modification ai plain rod or bar might be used inside-the tube a to give the expandingeiect instead .of using the expansion of the tube a itself.

regards the action of the thermostat, an ob'- vlous converse of that in the Fig. 1` arrangement, and the construction is somewhat sim'- In this case it is the outer or jacket tube or vessel b which by its expansion and contraction operates lthe feed-,control valve. To this end the tube b is connected. at its outer end to the Ilever g and completely incloses the tube a. The superheated fluid in the tube b is more or less cooled by the boiler water in the tube a,

its mean temperature being made to depend upon the rate of heat exchange through the walls of the inner tube a. Hence the length of the outer tube b varies according to this rate of the heat-exchange that is according to the water level, and thus the valve or device f is in. turn operated in the desired manner. In this case the pipes bx and b as'before represent respectively the inlet and outlet for the superheate'd steam in the jacket. l v

In any of the arrangements, the device j may' be simply any convenient valveadapted to control the flow of feed water into the boiler from a suitable high pressure supply. Such an arrangement is indicated in Figs. 4 and 5 where f3 is the water supply pipe from a high pressure source and f4 the 115 pipe for leading sucha water direct into the boiler when the device f permits it to iiow.

In the arrangement shown diagrammatically in Fig. 6, the necessity for a steam 1 jacket is obviated andthe construction -is correspondingly simplified. In this case the expansible device or tube a is heated by a gas-burner arrangement` Z. When the bollerwater is at the proper level,the tube 1s prevented by it from being heated beyond-125,1;

a certain point. When however the water level falls, the heat from the gas burner (having practically nothing to counteract it) expands' the empty tube, and the latter through the medium of the lever g (operata .er

fnot necessary even for the apparatus to be directly attached to or mounted on the iboiler, as the tube a of the heat exchanger may be placed in communication with the water space by a suitable connecting pipe which may be jacketed to prevent cooling. Moreover when the tube a is arranged to be heated as in Fig. 6, such heating may be effected by an electrical or an oil or paraiiin heater or otherwise as desired.

What we claim as our invention and desire to secure by Letters Patent in the United States is t' 1. In a thermostatic apparatus for regulating the level of liquid in a steam generator or the like, the combination of a tube or chamber which the liquid enters when at the proper level, means for heating such tube or chamber to a higher temperature than the boiler steam and for using the boiler liquid and steam .in opposition to` such heating means so as to produce the desired expansion or contraction of said tube or chamber, and means for enabling such expansion and contraction to control the supply of liquid, substantially as described.V

2. In a thermostatic apparatus for regulating the level of water in a steam boiler or the like, the combination of an external tube or chamber which the water enters when at the proper level, means for heating such tube or chamber to a higher temperature than the boiler steam and forusing the boiler water in opposition to such heating means so as to varythe expansion or contraction of said tube or chamber, and means for enabling such expansion and contraction to control the supply of water, substantially as described.

3. In a thermostatic apparatus for regulating the level of liquid in a steam generator or the like, the combination of an' external tube or chamber having its interior in communication with the water space at the water level, a steam jacket for said tube or chamber supplied with superheated steam, and means for 'controlling the feed supply by the expansion and contraction of said tube or chamber, substantially as described. Y

4. Ina thermostatic apparatus for regulating the level of liquid in a steam generator or the like, the combination of an exterinal eXpansible tube o r chamber having its interior in communication with the water space at the water level, a steam jacket for said tube or chamber supplied with superheated steam, an inextensible device, a `valve for controlling the feed, and a valve-operating lever connected both with said inextensible device and said eXpansible tube, substantially as described.

5. In a thermostatic apparatus for regulating the level of liquid in a steam generator or the like, the combination of an external expansible tube or chamber in free communication with the water space at the water level, a steam jacket for said tube or chamber supplied with superheated steam, an inextensible device situated in said jacket, a valve for controlling the feed, and a valveoperating lever connected with the tube and with said inextensible device, substantially as described.

v6. In a thermostatic apparatus for regulating the level of liquid in a steam generator or the like, the combination of an external expansible tube in free communication with the interior of the boiler at the water level, a jacket surrounding said tube, -a tube for superheated steam also ipclosed in said jacket along with the eXpansible tube, a

valve controlling the feed apparatus, a lever l connected with said expansible. tube and having one end acting on said valve, and a stationary support for the other end of the lever, substantially as described.

7.'In a thermostatic apparatus for regulating the level of liquid in a steam-generator, the combination of a horizontal tube opening into the boiler at the water'level, means for heating said tube to a temperature above that of the boiler steam, a feed control valve, an operating lever connected therewith, and means for operating said lever and valve on the occurrencev of an in-A crease in the temperature of the tube, substantially as described. s

8. In a thermostatic apparatus for regulating the water level in a boiler, the combi-I nation of a horizontall tube opening into the boiler at the proper. water level, a steam jacket for said tube, means for supplying superheated steam'to said jacket, a valve for controlling the boiler feed apparatus, and means for enabling said valve to be con- 'trolled by the expansion and contraction of the said jacket, substantially as described.

In testimony whereof we aiix our signatures in presence of two witnesses.

WALTER EAST. ARCHIBALD EDWARD DOBBS. JOHN SHIRLEY HOWKINS.y

Vitnesses to the signature of Archibald I Edward Dobbs: Y

PAUL KNABENSHUE, EDWARD HARVEY. Witnesses to the signatures of Walter East and John Shirley Howkins:

`HERBERT D. JAMESON, C. BARNARD BURDON. 

